A plasma reactor including a first dielectric having at least one slot defined therethrough, and a segmented electrode including a plurality of electrode segments, each electrode segment is disposed proximate an associated slot. Each electrode segment may be formed in different shapes, for example, a plate, bar, rim, or plug. The electrode segment may be hollow, solid, or made from a porous material. The reactor may include a second electrode and dielectric with the first and second dielectrics separated by a predetermined distance to form a channel therebetween into which the plasma exiting from the slots defined in the first dielectric is discharged. The fluid to be treated is passed through the channel and exposed to the plasma discharge. If the electrode segment is hollow or made of a porous material, then the fluid/gas to be treated may be fed into the slots defined in the first dielectric and exposed therein to the maximum plasma density. Thus, the fluid/gas to be treated may be exposed to the plasma discharge both in the slots as well as in the channel between the two dielectrics. The plasma reactor is more energy efficient than conventional devices and does not require a carrier gas to remain stable at atmospheric pressure. The plasma reactor has a wide range of application, such as the destruction of pollutants in a fluid, the generation of ozone, the pretreatment of air for modifying or improving combustion, and the destruction of various organic compounds, and surface cleaning of objects.